The invention relates to cosmetic compositions. More specifically, the invention relates to gel powder compositions with improved feel on application to skin.
Liquid powder compositions have become very popular in recent years for a number of reasons. Such compositions have an advantage over the traditional dusting powders in the mode of delivery is more precise; with a standard dusting powder, the user was forced to sprinkle the product over the areas where powder application was desired. Because of the light weight and particulate nature of powders generally, however, precise and limited application of the powder to the body was difficult. With liquid powders, however, the user simply smoothes the liquid product on the part of the body on which powder application is desired, and after a short time, the liquid evaporates, leaving behind the powder only where it is needed. Generally speaking, liquid powders are intended to be initially refreshing and smoothing to the skin, with the liquid base eventually transforming to a silky powder on the skin. Unlike other cosmetics that utilize powder components, for example mica, or other fillers used in color cosmetics, the user is intended to feel the powder on the skin, and to that end the powder components tend to be of a larger particle size than in other powder-containing cosmetics.
Liquid powders come in a variety of forms. All have in common the presence of a particulate powdery material combined with at least one volatile component. For example, U.S. Pat. Nos. 5,338,535 and 5,626,856 disclose non-aqueous liquid powders containing a volatile cyclomethicone combined with particulate carbohydrates such as cornstarch or tapioca. Non-aqueous compositions, however, can have a heavy or greasy feel when being applied initially, and thus may be less desirable for individuals with oily skin. Aqueous or alcoholic powder products are also known. These provide the advantage of a non-oily base, and thus can be more refreshing and cooling to apply and wear than oil-based, non-aqueous products. In such non-oily products, alcohol, water, or more typically, alcohol combined with water provide the volatile component, and the powder utilized is again primarily a starch such as tapioca or cornstarch.
In the majority of liquid powders, the particulate carbohydrates are the traditional powder components. This is primarily due to the cost of the materials, which is fairly low. Although effective in providing a powdery feel, however, these components can often leave a gritty uneven feeling on the skin when the volatile evaporates off. There thus continues to be a need for a liquid powder that provides the desirable cool feeling upon application and dry down, but which leaves a silky, smooth feeling on the skin when only the powder component remains.
The present invention relates to an liquid gel powder composition comprising a liquid carrier, and a powder component comprising at least one type of cosmetically acceptable spherical microparticle. In a preferred embodiment, the spherical microparticle is a silicone resin, a polyurethane particle, or a combination of both. The microparticles can form all or a part of the powder component of the composition.
The composition of the invention provides a cooling liquid powder composition that leaves a very smooth, powdery but non-gritty feeling on the skin when the volatile portion has evaporated off. It has been unexpectedly discovered that incorporation of spherical microparticles as all or a portion of the powder phase of an otherwise standard aqueous liquid powder composition confers a substantially different feel to the final product on the skin. Unlike the previously employed particulate carbohydrates, the particles of the invention are regularly spherical, and have a relatively uniform particle size distribution. In a preferred embodiment, the average particle diameter of the microspheres ranges from about 1-20xcexc. Particles of this type can be of a variety of chemical compositions, for example, nylon, silica, silicone resin, polyethylene, polyurethane, and acrylate or methacrylate polymers or copolymers. Particularly preferred among these microspheres are polyurethane and silicone resin microspheres. Examples of commercially available resins of these types are BPD-500, a polyurethane(HDI/trimethylyol hexyl lactone) microsphere, and Tospearl silicone resin (polymethylsilsesquioxane) microspheres, both available from Kobo Products, Inc., South Plainfield, N.J. Particularly preferred of the Tospearl microspheres is Tospearl 145, having an average particle diameter of about 4.5xcexc. Similar microspheres are also available from Presperse(Piscataway, N.J.).
The powder component of the composition comprises at least one type of spherical microparticle, but may also comprise a combination of microspheres. Overall, the powder component can comprise from about 1-30% by weight of the total composition, more preferably in the range of from 5-20%. The microspheres can be all or portion of the powder component; in other words, the spherical microparticles can be combined with other powder components. It has been unexpectedly discovered that a very desirable, soft, silky product can be obtained by the combination of the microspheres with a bulking agent or powder component. Examples of useful bulking agents are particulate carbohydrates e.g., starches, such as tapioca starch, corn starch, rice starch, potato starch, or wheat starch. Other useful bulking agents, particularly for non-aqueous products are amylopectin, agar, cellulose or a cellulose ether, glycogen, algin or carrageenan. Silica, nylon, polyethylene, polypropylene, mica, or talc could also be used. Starches are particularly preferred for aqueous gel powders. Particularly surprising is that even a relatively small proportion of microspheres can substantially improve the feel of the final product. Preferably, the starch and microspheres are present in a ratio of 5:1 to 1:5(starch to microspheres), more preferably 3:1 to 1.5:1. In fact, although a product containing all microspheres as powder component exhibits a silky powdery feel superior to that of an identical product containing all starch, a product containing a mixture of microspheres and starch exhibits an even better after-feel, and initially goes on more smoothly, with less tackiness, than either of the other products. In addition, the combination of starch and microspheres permits the formulation of an enhanced product with relatively little increase in expense over the product containing only starch.
The carrier can be any cosmetically acceptable liquid carrier, but is preferably one which has a volatile component that evaporates off the skin fairly rapidly. Particularly preferred is a gel base, which permits the suspension the powder and microparticle components. Preferably, the base is aqueous, and in a particularly preferred embodiment, the aqueous base is an aqueous gel. The gelling agent can be any which is appropriate for gelling an aqueous base, and includes, but is not limited to, carbomer, hydroxypropyl methylcellulose, hydroxyethylcellulose, hydroxy propyl guar, hydroxypropyl cellulose, or potato starch modified. Particularly preferred is an acrylates/C10-C30 alkyl acrylates crosspolymer, commercially available under the tradename Pemulen TR-2 from (B. F. Goodrich Specialty Chemicals, Cleveland, Ohio).
Although less preferred, the base may also be oily, or contain an oil component. A preferred oil base comprises a volatile oil, such as volatile cyclic and linear silicones, for example, cyclomethicone; or straight or branched chain hydrocarbons having from 8-20 carbon atoms, such as decane, dodecane, tridecane, tetradecane, and C8-20 isoparaffins. A preferred volatile oil is cyclomethicone. Useful oil gellants include, but are not limited to, organopolysiloxane elastomers, ethylene/methacrylic acid copolymer, ethylene/acrylic acid copolymer, or polyethylene.
Generally speaking, the liquid base component will constitute from about 10 to about 90%, preferably about 20 to about 60%, more preferably from about 30-50%, by weight of the total composition. The amount of gellant will vary depending upon the identity of the gellant, and the desired texture of the final product, but generally will be in the range of from about 0.1 to about 5% of the total composition.
There may be other optional components forming part of the composition. Since the liquid powder composition can be used for a variety of purposes, and not just as a body powder, it may be desirable to add additional components depending on the intended end use. In some cases, the desired components may not necessarily be soluble in an aqueous base. In such a case, it will be desirable to add an alcohol component to assist in solubilizing such components. The preferred alcohol component is a short chain, i.e., C1-C4 monohydric alcohol, such as methanol, ethanol or isopropanol. The alcohol also acts as a volatile to facilitate the rapid drying of the product. The alcohol component, if used will normally be present in an amount of from about 20-70% by weight.
In a particularly preferred embodiment, the composition is used as a body powder, preferably a fragranced body powder. In such a composition, fragrance will normally be added in an amount of from about 0.1-6% by weight of the composition. Such compositions can also contain standard cosmetic ingredients, such as colorants, preservatives, emulsifiers, skin conditioners, emollients, and the like. In addition to this embodiment, however, as noted above, the liquid powder composition can also be used for purposes other than a body powder. For example, it may be used as a delivery system to provide both cosmetic and pharmaceutical actives to the skin. Thus, in addition to the essential components of the invention, the composition can also comprise one or more active components. Examples of such active agents which may form part of the composition include, but are not limited to, those that improve or eradicate age spots, keratoses and wrinkles, analgesics, anesthetics, anti-acne agents, antibacterials, antiyeast agents, antifungal agents, antiviral agents, antidandruff agents, antidermatitis agents, antipruritic agents, antiemetics, antimotion sickness agents, anti-inflammatory agents, antihyperkeratolytic agents, anti-dry skin agents, antiperspirants, antipsoriatic agents, antiseborrheic agents, antiaging agents, antiwrinkle agents, antiasthmatic agents and bronchodilators, sunscreen agents, antihistamine agents, skin lightening agents, depigmenting agents, wound-healing agents, vitamins, corticosteroids, self-tanning agents, antioxidants, free-radical scavengers, or hormones. More specific examples of useful active agents include retinoids, topical cardiovascular agents, clotriiazole, ketoconazole, miconozole, griseofuilvin, hydroxyzine, diphenhydramine, pramoxine, lidocaine, procaine, mepivacaine, monobenzone, erythromycin, tetracycline, clindamycin, meclocyline, hydroquinone, minocycline, naproxen, ibuprofen, theophylline, cromolyn, albuterol, retinol, retinoic acid, 13-cis retinoic acid, hydrocortisone, hydrocortisone 21 -acetate, hydrocortisone 17-valerate, hydrocortisone 17-butyrate, betamethasone valerate, betamethasone diproprionate, triamcinolone acetonide, fluocinonide, clobetasol, proprionate, benzoyl peroxide, crotariton, propranolol, promethazine, vitamin A palmitate, vitamin E acetate, DHEA and derivatives thereof, alpha- or beta-hydroxy acids, and mixtures thereof. The amount of active agent to be used in any given formulation is readily determined in accordance with its usual dosage.